Sudden death in a case of sickle cell anemia: post-mortem computed tomography and autopsy correlation from a radiologist's perspective

Sickle cell anemia (SCA) is a hemolytic disease characterized by the production of abnormal hemoglobin chains and distorted red blood cell morphology or sickling. "Sickle cell crisis" includes vaso-occlusive crisis, a plastic crisis, sequestration crisis, haemolytic crisis and often culminating in serious complications, organ damage and even sudden death. Post-mortem computed tomography (PMCT) findings of sickle cell disease have never been reported in literature. This case of sudden death from acute hemolytic crisis in SCA where post-mortem computed tomography (PMCT) and autopsy findings complemented each other, both revealing findings invisible to the other and both crucial to the case.

Still frame from the hour of death: Acute intracerebral hemorrhage on post-mortem computed tomography in a decomposed corpse

We report a case of an acute hypertensive, intracerebral hemorrhage on post-mortem computed tomography (PMCT) in a decomposed corpse. In clinical radiology, the appearance of blood on cross-sectional imaging is used to estimate the age of intracranial hemorrhage. The findings from this case indicate that characteristics of intracerebral blood on PMCT provide a still frame of the hemorrhage, as it was at the time of death. This observation suggests that the appearance of blood on PMCT may be used to estimate the age of an intracerebral hemorrhage but not to estimate the post-mortem interval.

Added value of dual-energy computed tomography versus single-energy computed tomography in assessing ferromagnetic properties of ballistic projectiles: implications for magnetic resonance imaging of gunshot victims.

OBJECTIVE The objective of this study was to assess the discriminative power of dual-energy computed tomography (DECT) versus single-energy CT (SECT) to distinguish between ferromagnetic and non-ferromagnetic ballistic projectiles to improve safety regarding magnetic resonance (MR) imaging studies in patients with retained projectiles. MATERIALS AND METHODS Twenty-seven ballistic projectiles including 25 bullets (diameter, 3-15 mm) and 2 shotgun pellets (2 mm each) were examined in an anthropomorphic chest phantom using 128-section dual-source CT. Data acquisition was performed with tube voltages set at 80, 100, 120, and 140 kV(p). Two readers independently assessed CT numbers of the projectile's core on images reconstructed with an extended CT scale. Dual-energy indices (DEIs) were calculated from both 80-/140-kV(p) and 100-/140-kV(p) pairs; receiver operating characteristics curves were fitted to assess ferromagnetic properties by means of CT numbers and DEI. RESULTS Nine (33%) of the projectiles were ferromagnetic; 18 were nonferromagnetic (67%). Interreader and intrareader correlations of CT number measurements were excellent (intraclass correlation coefficients, >0.906; P<0.001). The DEI calculated from both 80/140 and 100/140 kV(p) were significantly (P<0.05) different between the ferromagnetic and non-ferromagnetic projectiles. The area under the curve (AUC) was 0.75 and 0.8 for the tube voltage pairs of 80/140 and 100/140 kV(p) (P<0.05; 95% confidence interval, 0.57-0.94 and 0.62-0.97, respectively) to differentiate between the ferromagnetic and non-ferromagnetic ballistic projectiles; which increased to 0.83 and 0.85 when shotgun pellets were excluded from the analysis. The AUC for SECT was 0.69 and 0.73 (80 and 100 kV[p], respectively). CONCLUSIONS Measurements of DECT combined with an extended CT scale allow for the discrimination of projectiles with non-ferromagnetic from those with ferromagnetic properties in an anthropomorphic chest phantom with a higher AUC compared with SECT. This study indicates that DECT may have the potential to contribute to MR safety and allow for MR imaging of patients with retained projectiles. However, further studies are necessary before this concept may be used to triage clinical patients before MR.

Reproducibility and accuracy of linear measurements on dental models derived from cone-beam computed tomography compared with digital dental casts.

INTRODUCTION The aim of this study was to determine the reproducibility and accuracy of linear measurements on 2 types of dental models derived from cone-beam computed tomography (CBCT) scans: CBCT images, and Anatomodels (InVivoDental, San Jose, Calif); these were compared with digital models generated from dental impressions (Digimodels; Orthoproof, Nieuwegein, The Netherlands). The Digimodels were used as the reference standard. METHODS The 3 types of digital models were made from 10 subjects. Four examiners repeated 37 linear tooth and arch measurements 10 times. Paired t tests and the intraclass correlation coefficient were performed to determine the reproducibility and accuracy of the measurements. RESULTS The CBCT images showed significantly smaller intraclass correlation coefficient values and larger duplicate measurement errors compared with the corresponding values for Digimodels and Anatomodels. The average difference between measurements on CBCT images and Digimodels ranged from -0.4 to 1.65 mm, with limits of agreement values up to 1.3 mm for crown-width measurements. The average difference between Anatomodels and Digimodels ranged from -0.42 to 0.84 mm with limits of agreement values up to 1.65 mm. CONCLUSIONS Statistically significant differences between measurements on Digimodels and Anatomodels, and between Digimodels and CBCT images, were found. Although the mean differences might be clinically acceptable, the random errors were relatively large compared with corresponding measurements reported in the literature for both Anatomodels and CBCT images, and might be clinically important. Therefore, with the CBCT settings used in this study, measurements made directly on CBCT images and Anatomodels are not as accurate as measurements on Digimodels.

Incidental findings on cone beam computed tomography scans in cleft lip and palate patients.

OBJECTIVES Cone beam computed tomography (CBCT) is frequently used in treatment planning for alveolar bone grafting (ABG) and orthognathic surgery in patients with cleft lip and palate (CLP). CBCT images may depict coincident findings. The aim of this study was to assess the prevalence of incidental findings on CBCT scans in CLP patients. SUBJECTS AND METHODS Initial CBCTs taken from consecutive patients (n = 187; mean age 11.7 years, range 6.9-45) with a non-syndromic orofacial cleft from January 2006 until June 2012 were systematically evaluated. Twenty-eight patients (mean age 19.3 years, range 13.2-30.9) had been subjected to ABG before their first CBCT was taken; 61 patients had a CBCT before and after ABG. Sinuses, nasopharynx, oropharynx, throat, skull, vertebrae, temporomandibular joint (TMJ), maxilla and mandible were checked for incidental findings. RESULTS On 95.1 % of the CBCTs, incidental findings were found. The most prevalent were airway/sinus findings (56.1 %), followed by dental problems, e.g. missing teeth (52 %), nasal septum deviation (34 %), middle ear and mastoid opacification, suggestive for otitis media (10 %) and (chronic) mastoiditis (9 %), abnormal TMJ anatomy (4.9 %) and abnormal vertebral anatomy (1.6 %). In the 28 patients whose first CBCT was taken at least 2 years after ABG, bone was still present in the reconstructed cleft area except in 2 out of 12 patients with a bilateral CLP. The ABG donor site (all bone grafts were taken from the chin area) was still recognizable in over 50 % of the patients. Based on the CBCT findings, 10 % of the patients were referred for further diagnosis and 9 % for further treatment related to dental problems. CONCLUSION Incidental findings are common on CBCTs. Compared with the literature, CLP patients have more dental, nasal and ear problems. Thus, whenever a CBCT is available, this scan should be reviewed by all specialists in the CLP team focusing on their specific background knowledge concerning symptoms and treatment of these patients. CLINICAL RELEVANCE The high number of findings indicates that CBCT imaging is a helpful tool in the treatment of CLP patients not only related to alveolar bone grafting and orthognathic surgery but it also provides diagnostic information for almost all specialties involved in CLP treatment.

Incidence of anatomical variations and disease of the maxillary sinuses as identified by cone beam computed tomography: a systematic review.

PURPOSE To analyze available evidence on the incidence of anatomical variations or disease of the maxillary sinuses as identified by cone beam computed tomography (CBCT) in dentistry. MATERIALS AND METHODS A focused question was developed to search the electronic databases MEDLINE, EMBASE, the Cochrane Oral Health Group Trials Register, and CENTRAL and identify all relevant papers published between 1980 and January 19, 2013. Unpublished literature at ClinicalTrials.gov, in the National Research Register, and in the Pro-Quest Dissertation Abstracts and Thesis database was also included. Studies were included irrespective of language. These results were supplemented by hand and gray literature searches. RESULTS Twenty-two studies were identified. Twenty were retrospective cohort studies, one was a prospective cohort study, and one was a case control study. The main indication for CBCT was dental implant treatment planning, and the majority of studies used a small field of view for imaging. The most common anatomical variations included increased thickness of the sinus membrane, the presence of sinus septa, and pneumatization. Reported sinus disease frequency varied widely, ranging from 14.3% to 82%. There was a wide range in the reported prevalence of mucosal thickening related to apical pathology, the degree of lumenal opacification, features of sinusitis, and the presence of retention cysts and polyps. More pathologic findings in the maxillary sinus were reported in men than in women, and the medial wall and sinus floor were most frequently affected. CONCLUSION CBCT is used primarily to evaluate bony anatomy and to screen for overt pathology of the maxillary sinuses prior to dental implant treatment. Differences in the classification of mucosal findings are problematic in the consistent and valid assessment of health and disease of the maxillary sinus.

Bone dimensions in the posterior mandible: a retrospective radiographic study using cone beam computed tomography. Part 2- analysis of edentulous sites.

A precise radiographic evaluation of the local bone dimensions and morphology is important for preoperative planning of implant placement. The purpose of this retrospective study was to analyze dimensions and morphology of edentulous sites in the posterior mandible using cone beam computed tomography (CBCT) images. This retrospective radiographic study measured the bone width (BW) of the mandible at three locations on CBCT scans for premolars (PM1, PM2) and molars (M1, M2): at 1 mm and 4 mm below the most cranial point of the alveolar crest (BW1, BW2) and at the superior border of the mandibular canal (BW3). Furthermore, the height (H) of the alveolar process (distance between the measuring points BW1 and BW3), as well as the presence of lingual undercuts, were analyzed. A total of 56 CBCTs met the inclusion criteria, resulting in a sample size of 127 cross sections. There was a statistically significant increase from PM1 to M2 for the BW2 (P < .001), which was not present for BW1 and BW3 values. For the height of the alveolar process, the values exhibited a decrease from PM1 to M2 sites. Sex was a statistically significant parameter for H (P = .001) and for BW1 (P = .03). Age was not a statistically significant parameter for bone width (BW1: P = .37; BW2: P = .31; BW3: P = .51) or for the height of the alveolar process (P = .41) in the posterior mandible. Overall, 73 (57.5%) edentulous sites were evaluated to be without visible lingual undercuts; 13 (10.2%) sites exhibited lingual undercuts classified as influential for implant placement. Precise evaluation of the alveolar crest by cross-sectional imaging is of great value to analyze vertical and buccolingual bone dimensions in different locations in the posterior mandible. In addition, CBCTs are valuable to diagnosing the presence of and potential problems caused by lingual undercuts prior to implant placement.

Proximity of premolar roots to maxillary sinus: a radiographic survey using cone-beam computed tomography.

INTRODUCTION The proximity of the roots of the posterior maxillary teeth to the maxillary sinus is a constant challenge to the dental practitioner. Because the majority of studies have assessed the relationship regarding molars, the present study focused on premolars. METHODS Cone-beam computed tomographic images of 192 patients were reconstructed in sagittal, coronal, and axial planes to quantify the distances between the root apices of the maxillary premolars and the adjacent maxillary sinus. Measurements were taken for each root, and data were correlated with age, sex, side, and presence of both or absence of 1 of the 2 premolars. RESULTS A total of 296 teeth (177 first and 119 second premolars) were evaluated. The mean distances from buccal roots of the first premolars to the border of the maxillary sinus in the sagittal, coronal, and axial planes ranged from 5.15 ± 2.99 to 8.28 ± 6.27 mm. From palatal roots, the mean distances ranged from 4.20 ± 3.69 to 7.17 ± 6.14 mm. The mean distances of second premolars were markedly shorter in buccal roots between 2.32 ± 2.19 and 3.28 ± 3.17 mm and in palatal roots between 2.68 ± 3.58 and 3.80 ± 3.71 mm, respectively. The frequency of a premolar root protrusion into the maxillary sinus was very low in first premolars (0%-7.2%) but higher in second premolars (2.5%-13.6%). Sex, age, side, and presence/absence of premolars failed to significantly influence the mean distances between premolar roots and the maxillary sinus. CONCLUSIONS Based on the calculated mean distances of the present study, only few premolars (and if so second premolars) would present a risk of violating the border of the maxillary sinus during conventional or surgical endodontic treatment or in case of tooth extraction.

Three-dimensional study of nasopalatine canal morphology: a descriptive retrospective analysis using cone-beam computed tomography

PURPOSE For dental implant treatment planning and placement, a precise anatomic description of the nasopalatine canal (NC) is necessary. This descriptive retrospective study evaluated dimensions of the NC and buccal bone plate (BBP) and the tridimensional association of the anatomic variants of NC, using cone-beam computed tomography (CBCT). METHODS This study included 230 CBCTs. Sagittal slices were used for measurements of the NC and BBP and to evaluate shape and direction-course of the NC. Coronal slices were used to assess NC shape and axial slices to assess number of incisive foramina and foramina of Stenson. RESULTS Mean NC length was 12.34 ± 2.79 mm, statistically significant differences were detected between genders (p < 0.001). Mean BBP length was 20.87 ± 3.68 mm, statistically significant differences were found for the dental status (p < 0.001) and mean BBP width was 6.83 ± 1.28 mm, significant differences were detected between genders (p < 0.001). Mean nasopalatine angle was 73.33° ± 8.11°, significant differences were found in sagittal and coronal classifications. The most prevalent canal was: cylindrical sagittal shape (48.2 %); slanted-straight direction-course (57.6 %); Ya-type coronal shape (42.4 %); and one foramen incisive with two Stenson's foramina (1-2) (50.9 %). Sagittal shape was associated with sagittal direction-course (p < 0.001). Coronal shape was associated with axial classification (p < 0.001). CONCLUSIONS The NC anatomy is highly variable. Gender is related to the NC length and BBP width, while dental status is related to BBP length. There was an association between the different sagittal classifications of the NC and between the coronal shape and axial classification.

Cone beam computed tomography in implant dentistry: a systematic review focusing on guidelines, indications, and radiation dose risks.

PURPOSE The aim of the paper is to identify, review, analyze, and summarize available evidence in three areas on the use of cross-sectional imaging, specifically maxillofacial cone beam computed tomography (CBCT) in pre- and postoperative dental implant therapy: (1) Available clinical use guidelines, (2) indications and contraindications for use, and (3) assessment of associated radiation dose risk. MATERIALS AND METHODS Three focused questions were developed to address the aims. A systematic literature review was performed using a PICO-based search strategy based on MeSH key words specific to each focused question of English-language publications indexed in the MEDLINE database retrospectively from October 31, 2012. These results were supplemented by a hand search and gray literature search. RESULTS Twelve publications were identified providing guidelines for the use of cross-sectional radiography, particularly CBCT imaging, for the pre- and/or postoperative assessment of potential dental implant sites. The publications discovered by the PICO strategy (43 articles), hand (12), and gray literature searches (1) for the second focus question regarding indications and contraindications for CBCT use in implant dentistry were either cohort or case-controlled studies. For the third question on the assessment of associated radiation dose risk, a total of 22 articles were included. Publication characteristics and themes were summarized in tabular format. CONCLUSIONS The reported indications for CBCT use in implant dentistry vary from preoperative analysis regarding specific anatomic considerations, site development using grafts, and computer-assisted treatment planning to postoperative evaluation focusing on complications due to damage of neurovascular structures. Effective doses for different CBCT devices exhibit a wide range with the lowest dose being almost 100 times less than the highest dose. Significant dose reduction can be achieved by adjusting operating parameters, including exposure factors and reducing the field of view (FOV) to the actual region of interest.

Fluoroscopic anatomy of left-sided heart structures for transcatheter interventions: insight from multislice computed tomography.

With the introduction of transcatheter structural heart therapies, cardiologists are increasingly aware of the importance of understanding anatomical details of left-sided heart structures. Understanding fluoroscopic cardiac anatomy can facilitate optimal positioning and deployment of prostheses during transcatheter valve repair/replacement, left atrial appendage occlusion, septal defect closure, and paravalvular leak closure. It is possible to use multislice computed tomography to determine optimal fluoroscopic viewing angles for such transcatheter therapies. The purpose of this paper is to describe how optimal fluoroscopic viewing angles of left-sided heart structures can be obtained using computed tomography. Two- and 3-chamber views are described and may become standard in the context of transcatheter structural heart interventions.

Morphologic characteristics, location, and associated complications of maxillary and mandibular supernumerary teeth as evaluated using cone beam computed tomography.

OBJECTIVES To evaluate the location and morphologic characteristics of supernumerary teeth and to assess the frequency and extent of root resorption of adjacent teeth using cone beam computed tomography (CBCT). MATERIALS AND METHODS CBCT scans of 82 patients with supernumerary teeth in the maxilla and mandible were evaluated by two orthodontists independently. Data regarding the type, shape, and three-dimensional (3D) location of the supernumeraries including the frequency and extent of root resorption of adjacent teeth were recorded and evaluated for possible associations. RESULTS The study comprised a total of 101 supernumerary teeth. Most of the patients (80.5 per cent) exhibited one single supernumerary tooth, while 15.8 per cent had two and 3.7 per cent had three supernumeraries. Males were affected more than females with a ratio of 1.65:1. Mesiodentes were the most frequently diagnosed type of supernumerary teeth (48.52 per cent), followed by supernumerary premolars (23.76 per cent) and lateral incisors (18.81 per cent). Supernumeraries were most commonly conical in shape (42.6 per cent) with a normal or inclined vertical position (61.4 per cent). Root resorption of adjacent teeth was detected for 22.8 per cent of the supernumerary teeth, most frequently for supernumerary premolars. There was a significant association between root resorption of adjacent teeth and type and shape of tooth. Interrater agreement for the measurements performed showed kappa values ranging from 0.55 to 1 with a kappa value of 1 for type and shape of the supernumerary teeth. CONCLUSIONS CBCT provides 3D information about location and shape of supernumerary teeth as well as prevalence and degree of root resorption of neighbouring teeth with moderate to high interrater correlation.

Comparison of the critical shoulder angle in radiographs and computed tomography.

OBJECTIVE The critical shoulder angle (CSA) is an indicator of degenerative shoulder pathologies. CSAs above 35° are associated with degenerative rotator cuff disease, whereas values below 30° are common in osteoarthritis of the glenohumeral joint. Measurements are usually performed on radiographs; however, no data have been reported regarding the reliability of CT scan measurements between different readers or the reproducibility of measurements from radiographs to CT scans. The purpose of our study was to clarify whether CSA measurements on radiographs and CT scans of the same patients show similar values. MATERIALS AND METHODS CSA measurements of 60 shoulders (59 patients) were performed on radiographs and multiplanar reconstructions of corresponding CT scans. Inter-reader reliability and inter-method correlation were calculated. RESULTS The mean discrepancy between readers was only 0.2° (SD ±1.0°) on radiographs. CT scan measurements showed a mean discrepancy of 0.3° (SD ±1.2°). The inter-reader reliability was 0.993 for radiographs and 0.989 for CT scans. There was a very strong inter-method correlation between the CSA measured on radiographs and CT scans (Spearman's rho = 0.974). The mean differences between angles on radiographs and CT measurements were -0.05° (SD ±1.2°) and 0.1° (SD ±1.2°), respectively. CONCLUSION Measurements of the CSA on anterior-posterior radiographs and CT scans are highly correlated, and inter-modality differences are negligible.

Is fast track management after elective cranial surgery safe and can it replace routine early postoperative computed tomography?

Aims: Patient management following elective cranial surgery varies between different neurosurgical institutions. Early routine postoperative cranial computed tomography (CT) is often performed while keeping patients sedated and ventilated for several hours. We hypothesize that fast track management without routine CT scanning, i.e., early extubation within one hour allowing neurological monitoring, is safe and does not increase the rate of return to OR compared with published data. Methods: We prospectively screened 1118 patients with cranial procedures performed at our department over a period of two years. 420 patients with elective brain surgery older than 18 years with no history of prior cranial surgery were included. Routine neurosurgical practice as it is performed at our department was not altered for this observational study. Fast track management was aimed for all cases, extubated and awake patients were further monitored. CT scanning within 48 hours after surgery was not performed except for unexpected neurological deterioration. This study was registered at ClinicalTrials.gov (NCT01987648). Results: 420 elective craniotomies were performed for 310 supra- and 110 infratentorial lesions. 398 patients (94.8%) were able to be extubated within 1 hour, 21 (5%) within 6 hours, and 1 patient (0.2%) was extubated 9 hours after surgery. Emergency CT within 48 hours was performed for 36 patients (8.6%, 26 supra- and 10 infratentorial cases) due to unexpected neurological worsening. Of these 36 patients 5 had to return to the OR (hemorrhage in 3, swelling in 2 cases). Return to OR rate of all included cases was 1.2%. This rate compares favorably with 1-4% as quoted in the current literature. No patient returned to the OR without prior CT imaging. Of 398 patients extubated within one hour 2 (0.5%) returned to the OR. Patients who couldn’t be extubated within the first hour had a higher risk of returning to the OR (3 of 22, i.e., 14%). Overall 30-day mortality was 0.2% (1 patient). Conclusions: Early extubation and CT imaging performed only for patients with unexpected neurological worsening after elective craniotomy procedures is safe and does not increase patient mortality or the return to OR rate. With this fast track approach early postoperative cranial CT for detection of postoperative complications in the absence of an unexpected neurological finding is not justified. Acknowledgments The authors thank Nicole Söll, study nurse, Department of Neurosurgery, Bern University Hospital, Switzerland for crucial support in data collection and managing the database.